Moretti was the godfather with then unknown singer Frank Sinatra. Sinatra's first wife, Nancy Barbato, was a paternal cousin of John Barbato, a Moretti associate. Moretti helped Sinatra get bookings in New Jersey clubs in return for kickbacks. Finally, in 1939, Sinatra signed a recording contract with band leader Tommy Dorsey. However, by the early 1940s, Sinatra had achieved national popularity and wanted to sign a more lucrative recording contract, but Dorsey refused to release him from their existing contract. A rumour claimed that Sinatra asked Moretti for help, and it was alleged that Moretti jammed a gun barrel down Dorsey's throat and threatened to kill him if he did not release Sinatra. Dorsey eventually sold the contract to Sinatra for one dollar. [3]

In the late 1940s, Moretti become acquainted with comedians Dean Martin and Jerry Lewis while they were performing at Bill Miller's Riviera nightclub in Fort Lee, New Jersey. In earlier years, Moretti and Abner "Longy" Zwillman were watching the club's cardroom when it was previously owned by Ben Marden. In 1947, Martin, Lewis, Sinatra, and comedian Milton Berle all performed at the wedding reception of Moretti's daughter. Another friend of Moretti, Louis Mastrola, a local nightclub entertainer who performed under the stage name, Louie Mass, also entertained at the reception.

In 1950, the U.S. Senate Select Committee on Organized Crime started an investigation known as the Kefauver hearings, named after its chairman, Sen. Estes Kefauver. Along with other members of Genovese family, Moretti, by then widely known by his alias "Willie Moore," was called to testify. Moretti was the only one who cooperated with the committee. While the other mobsters refused to testify by repeatedly invoking the Fifth Amendment to the United States Constitution, which provides legal protection against self-incrimination, the garrulous Moretti told jokes, spoke candidly, and generally played it up for the cameras. For example, when asked how long he'd been in the Mafia he replied, "What do you mean, like do I carry a membership card that says 'Mafia' on it?" And when asked how he operated politically he said, "I don't operate politically, if I did I'd be a congressman." The Senators and spectators in the room broke out laughing at his responses. In doing so, however, he was violating the Mafia code of silence, known as omertà.

As it was being alleged that Moretti's mental condition was possibly deteriorating from advanced stage syphilis,[4] it was feared he was becoming too talkative. An open contract was placed by the mob commission to have him killed. Twelve years later, government witness Joe Valachi described a conversation with Genovese crime family boss Vito Genovese about the Moretti murder:

"It was supposedly a mercy killing because he was sick. Genovese told me, 'The Lord have mercy on his soul, he's losing his mind.'"[5]

On October 4, 1951, Moretti was lunching with four other men at Joe's Elbow Room Restaurant in Cliffside Park, New Jersey. The waitress remembered the men, the only patrons in the restaurant, joking together in Italian before she went into the kitchen. At 11:28 am, the restaurant staff heard shots fired and ran into the dining room. Moretti was lying dead on his back on the floor with bullet wounds to the face and head. By some accounts, the shots to his face were a sign of respect. The gunmen had already fled the restaurant.[1]

On the day of Moretti's murder, Martin and Lewis had a lunch date scheduled with Moretti. However, earlier that morning, Lewis learned that he had contracted the mumps and both men totally forgot about lunch. Later, while trying to reach Moretti to apologize and explain, they learned from the television news that he was dead (Lewis 2005).